An Ionic Nickel(II) Phosphate with Ethylenediamine: (C2H10N2)[Ni(H2O)6](HPO4)2. Hydrothermal Synthesis, Crystal Structure, and Spectroscopic Properties

An ionic nickel(II) phosphate templated by ethylenediamine, (C2H10N2)[Ni(H2O)6](HPO4)2, has been prepared by hydrothermal synthesis and characterized by single-crystal diffraction data and spectroscopic techniques. The compound crystallizes in the monoclinic space group P21/c with a=6.226(1), b=16.241(2), and c=14.778(2) ?, beta=91.28(1)°, V=1493.9(4) ?3, and Z=4. The structure consists of isolated Ni(H2O)6 octahedra and HPO4 tetrahedra, both of them hydrogen-bonded to ethylenediammonium cations. The compound has been characterized by IR spectroscopy, showing the bands characteristic of the (HPO4)2- anions and the ethylenediammonium cation. Diffuse reflectance measurements indicate the presence of octahedrally coordinated Ni(II) ions. The Dq (835 cm-1) and Racah (B=900, C=4040 cm1) parameters have been calculated for the Ni(II) ions in octahedral sites.